IAD05LA075

NTSB accident investigation · Hughes TH-55 · Paintsville, KY · June 6, 2005

Accident · Minor injuriesLimited investigationFinal report
Date
June 6, 2005, 18:00 local (22:00 UTC)
Place
Paintsville, KY
Injuries
1 minor
Damage
Destroyed
Phase of flight
Takeoff
Aircraft
N2KXHughes TH-55
Weather
Visual (VMC) · Day
Status
Completed · report April 25, 2006
Report
Approved by Office Director
Parties
FAA/FSDO
FAA report
20050606012719A
Case key
61674

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

the pilot's inadvertent encounter with ground resonance which resulted in destruction of the helicopter.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Roll overTakeoff
Ground resonance - inadvertentPilot in commandCause
Terrain condition - ground

Analysis

The purpose of the flight was to perform a cyclic-rigging check, and a rotor-rpm check during autorotation. The pilot and a friend performed a preflight inspection, and neither noted any mechanical deficiencies. The pilot started the helicopter, and performed the run-up checks, to include the magneto check and the rotor-engagement check with the helicopter "light on the skids." The pilot then completed the before takeoff checks, and initiated a takeoff to a hover. As the pilot applied collective pitch and power for takeoff, he felt a few bumps. He was aware of the phenomena of ground resonance, and continued applying collective pitch and power, but the helicopter would not take off. Within seconds, he had no control of the helicopter, as it disintegrated around him. The friend's version of the events leading up to the accident was consistent with the pilot/owner's. According to the witness, "It happened so fast! It started to shake, a blade hit the tailboom, and it shook to pieces." He added that the helicopter never left the ground, and that it rocked side-to-side two or three times before it came apart.

Factual narrative

On June 6, 2005, at 1800 eastern daylight time, a 1966 Hughes TH-55 helicopter, N2KX, was destroyed during an attempted takeoff from the Paintsville-Prestonsburg-Combs Field Airport (3I6), Paintsville, Kentucky. The certificated private pilot/owner received minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91.

In a telephone interview, the pilot/owner explained that the purpose of the flight was to perform a cyclic-rigging check, and a rotor-rpm check during autorotation.

The pilot/owner loaned the helicopter to a friend for about 20 hours of flight instruction. The friend returned the helicopter, and said that it "didn't feel right," but was unable to identify the reason for his discomfort. The two then flew the helicopter, and the owner said the cyclic felt "out of rig" because it was aft of its nominal position during cruise flight. During autorotation, the main rotor reached its rpm limit, and nearly over sped.

The pilot and his friend subsequently met on the day of the accident to troubleshoot the helicopter. They each performed a preflight inspection, and neither noted any mechanical deficiencies.

The pilot started the helicopter, and performed the run-up checks, to include the magneto check and the rotor-engagement check. These checks were performed at operating rpm, with the helicopter "light on the skids."

The pilot then completed the before takeoff checks, and initiated a takeoff to a hover. According to the pilot, "I pulled it up to a hover, and I'm not sure what happened after that. I mean, I pulled up on the collective, and it went all to pieces."

As the pilot applied collective pitch and power for takeoff, he felt a few bumps. He was aware of the phenomena of ground resonance, and continued applying collective pitch and power, but the helicopter would not take off. Within seconds, he had no control of the helicopter, as it disintegrated around him. He also recalled sensing that the main rotor struck the tailboom, but couldn't recall when in the sequence that it took place.

The pilot's friend stood about 100 feet away and witnessed the accident. His version of the events leading up to the accident was consistent with the pilot/owner's. He described the engine start and the run-up checks, and said that he anticipated the takeoff.

According to the witness, "It happened so fast! It started to shake, a blade hit the tailboom, and it shook to pieces." He added that the helicopter never left the ground, and that it rocked side-to-side two or three times before it came apart.

The helicopter had accrued 4,848 total flight hours. Its most recent annual inspection was completed April 24, 2005, at 4,822 aircraft hours.

The pilot held a commercial pilot certificate with ratings for airplane single engine land, and instrument airplane, and a private pilot certificate with a rating for rotorcraft-helicopter. He also held a flight instructor certificate with a rating for airplane single engine, and mechanic certificate with a rating for airframe.

The pilot was issued a Federal Aviation Administration (FAA) second-class medical certificate on December 9, 2003. He reported 2,200 total hours of flight experience on that date. The pilot estimated that he had 170 total hours of experience in helicopters, 150 hours of which were in make and model.

At 1753, the weather reported at Julian Carroll Airport (JKL), Jackson, Kentucky, about 27 miles west, included clear skies, calm winds, and 10 statute miles of visibility.

Aircraft

Registration
N2KX
Reported as
Hughes TH-55
Category
Helicopter
Serial number
66-18349
Airframe hours
4,848
Engine
Lycoming HIO-360-B1A, 180 horsepower, reciprocating
Damage
Destroyed
Flight
Personal · Part 91
Registered owner
Stanley D. Haddix
Airworthiness certificate
Standard, Normal
Last inspection
Annual · April 1, 2005 · 26 hours before
Departed
3I6 · Paintsville, KY
Destination
3I6
Airport
3I6 · Paintsville-Prestonsburg-Combs

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
48
Injuries
Minor
Certificates
Private, Flight instructor, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
August 1, 2004
Seat
Right
Flight hours
2,200 total · 150 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
90 °F, dew point 63 °F
Altimeter
29.94 inHg
Observed at
JKL, 27 nm away

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.